In algebra the notation is basically just a number, for example, 10, and we take it to the 10th power, you just take the decimal at the end of the 10 and move it 10 spaces to the right, if the number is negative you will move the decimal to the left 10 spaces, the 10th power is a variable and is different with every question
The radius is always half of the diameter so it would be 20 inches
I think it’s the first one because if you look at the shape it lines up to make the same shape Srry if this is wrong
